
#include "cmd_xmodem.h"
#include "command.h"
#include "string.h"
#include "ring_buffer.h"
#include "usart.h" 
#include "sys.h"
#include "delay.h"
#include "malloc.h"

static int last_error = 0;
 
void port_outbyte( u8 trychar)
{
	uart_send_char( trychar );
}

unsigned char port_inbyte(unsigned int time_out)
{
	unsigned int time_cnt=0;
	unsigned char ch;
	last_error = 0;
	
	while ( time_cnt++ < 1000*time_out )
	{
		if( ring_buffer_read( &uart_rx , &ch , 1 ) == 1)
			return ch;
		delay_us ( 1 );
/*		if ( rx_flag )
		{
			rx_flag = 0;
			return rx_data;
		}*/
	}
	
	last_error = 1;
	return ch;
}

static int check(int crc, unsigned char *buf, int sz)
{
	int i;
	unsigned short crc_tmp;
	unsigned short tcrc_tmp;
	unsigned char cks = 0;
	if (crc)
	{
		crc_tmp = crc16_ccitt(buf, sz);
		tcrc_tmp = (buf[sz]<<8)+buf[sz+1];
		if (crc_tmp == tcrc_tmp)
			return 1;
	}
	else
	{
		for (i = 0; i < sz; ++i)
		{
			cks += buf[i];
		}
		if (cks == buf[sz])
			return 1;
	}

	return 0;
}

static void flushinput(void)
{
 //while (port_inbyte(((DLY_1S)*3)>>1) >= 0)
  ;
}

int xmodemReceive(unsigned char *dest, int destsz)
{
	unsigned char xbuff[1030];
	unsigned char *p;
	int bufsz, crc = 0;
	unsigned char trychar = 'C';
	unsigned char packetno = 1;
	int i, c, len = 0;
	int retry, retrans = MAXRETRANS;
	int count;

	for(;;)
	{
		for( retry = 0; retry < 16; ++retry)
		{
			if (trychar)
				port_outbyte(trychar);
			c = port_inbyte((DLY_1S)<<1);
			if (last_error == 0)
			{
				switch (c)
				{
					case SOH:
						bufsz = 128;
						goto start_recv;
					case STX:
						bufsz = 1024;
						goto start_recv;
					case EOT:
						flushinput();
						port_outbyte(ACK);
						return len;
					case CAN:
						c = port_inbyte(DLY_1S);
						if (c == CAN)
						{
							flushinput();
							port_outbyte(ACK);
							return -1;
						}
						break;
					default:
						break;
				}
			}
		}
		if (trychar == 'C')
		{
			trychar = NAK;
			continue;
		}
		flushinput();
		port_outbyte(CAN);
		port_outbyte(CAN);
		port_outbyte(CAN);
		return -2;

start_recv:
		if (trychar == 'C') 
			crc = 1;
		trychar = 0;
		p = xbuff;
		*p++ = c;
		for (i = 0;  i < (bufsz+(crc?1:0)+3); ++i)
		{
			c = port_inbyte(DLY_1S);
			if (last_error != 0)
				goto reject;
			*p++ = c;
		}

		if ( xbuff[1] == (unsigned char)(~xbuff[2]) && 
			(xbuff[1] == packetno || xbuff[1] == 
			(unsigned char)packetno-1) &&
			check(crc, &xbuff[3], bufsz))
		{
			if (xbuff[1] == packetno) 
			{
				count = destsz - len;
				if (count > bufsz)
				count = bufsz;
				if (count > 0)
				{
					memcpy (&dest[len], &xbuff[3], count);
					len += count;
				}
				++packetno;
				retrans = MAXRETRANS+1;
			}
			if (--retrans <= 0)
			{
				flushinput();
				port_outbyte(CAN);
				port_outbyte(CAN);
				port_outbyte(CAN);
				return -3;
			}
			port_outbyte(ACK);
			continue ;
		}
reject:
		flushinput();
		port_outbyte(NAK);
	}
}

int xmodemTransmit(unsigned char *src, int srcsz)
{
	unsigned char xbuff[1030];
	int bufsz, crc = -1;
	unsigned char packetno = 1;
	int i, c, len = 0;
	int retry;

	for(;;) 
	{
		for( retry = 0; retry < 16; ++retry)
		{
			c = port_inbyte((DLY_1S)<<1);
			if (last_error == 0)
			{
				switch (c)
				{
					case 'C':
						crc = 1;
						goto start_trans;
					case NAK:
						crc = 0;
						goto start_trans;
					case CAN:
						c = port_inbyte(DLY_1S);
						if (c == CAN)
						{
							port_outbyte(ACK);
							flushinput();
							return -1;
						}
						break;
					default:
						break;
				}
			}
		}
		port_outbyte(CAN);
		port_outbyte(CAN);
		port_outbyte(CAN);
		flushinput();
		return -2;

		for(;;)
		{
			start_trans:
			xbuff[0] = SOH; bufsz = 128;
			xbuff[1] = packetno;
			xbuff[2] = ~packetno;
			c = srcsz - len;
			if (c > bufsz) 
				c = bufsz;
			if (c >= 0)
			{
				memset (&xbuff[3], 0, bufsz);
				if (c == 0)
				{
					xbuff[3] = CTRLZ;
				}
				else
				{
					memcpy (&xbuff[3], &src[len], c);
					if (c < bufsz) 
						xbuff[3+c] = CTRLZ;
				}
				if (crc)
				{
					unsigned short ccrc = crc16_ccitt(&xbuff[3], bufsz);
					xbuff[bufsz+3] = (ccrc>>8) & 0xFF;
					xbuff[bufsz+4] = ccrc & 0xFF;
				}
				else
				{
					unsigned char ccks = 0;
					for (i = 3; i < bufsz+3; ++i)
					{
					ccks += xbuff[i];
					}
					xbuff[bufsz+3] = ccks;
				}
				for (retry = 0; retry < MAXRETRANS; ++retry)
				{
					for (i = 0; i < bufsz+4+(crc?1:0); ++i)
					{
						port_outbyte(xbuff[i]);
					}
					c = port_inbyte(DLY_1S);
					if (last_error == 0 )
					{
						switch (c)
						{
							case ACK:
								++packetno;
								len += bufsz;
								goto start_trans;
							case CAN:
								c = port_inbyte(DLY_1S);
								if ( c == CAN)
								{
								port_outbyte(ACK);
								flushinput();
								return -1;
								}
								break;
							case NAK:
							default:
								break;
						}
					}
				}
				port_outbyte(CAN);
				port_outbyte(CAN);
				port_outbyte(CAN);
				flushinput();
				return -4;
			}
			else
			{
				for (retry = 0; retry < 10; ++retry)
				{
					port_outbyte(EOT);
					c = port_inbyte((DLY_1S)<<1);
					if (c == ACK) 
						break;
				}
				flushinput();
				return (c == ACK)?len:-5;
			}
		}
	}
}

int do_xmodem ( int argc , char **argv )
{
	u32 ram_addr;
	int length;
	unsigned char *pt;
	
	if ( argc != 4 )
		goto ERR;
	ram_addr = str2hex ( argv[2] );
	length = str2hex ( argv[3] );
 	if ( length == 0xFFFFFFFF )
 		goto ERR;

	pt = (unsigned char*)ram_addr;
	if ( 0 == strcmp ( "rec" , argv[1] ) )
	{
		printf ( "Start XModem Receive file to 0x%08X...\r\n" , ram_addr ) ;
		xmodemReceive ( pt , length );
	}
	else if ( 0 == strcmp ( "send" , argv[1] ) )
	{
		printf ( "Start XModem Send file at 0x%08X...\r\n" , ram_addr ) ;
		xmodemTransmit ( pt , length );
	}
	ram_pt = pt;
	return 0;
ERR:
	return -1;
}

